title: Frontoparietal cortex mediates perceptual transitions in bistable perception.
abstract: During bistable vision, perception oscillates between two mutually exclusive percepts despite constant sensory input. Greater BOLD responses in frontoparietal cortex have been shown to be associated with endogenous perceptual transitions compared with "replay" transitions designed to closely match bistability in both perceptual quality and timing. It has remained controversial, however, whether this enhanced activity reflects causal influences of these regions on processing at the sensory level or, alternatively, an effect of stimulus differences that result in, for example, longer durations of perceptual transitions in bistable perception compared with replay conditions. Using a rotating Lissajous figure in an fMRI experiment on 15 human participants, we controlled for potential confounds of differences in transition duration and confirmed previous findings of greater activity in frontoparietal areas for transitions during bistable perception. In addition, we applied dynamic causal modeling to identify the neural model that best explains the observed BOLD signals in terms of effective connectivity. We found that enhanced activity for perceptual transitions is associated with a modulation of top-down connectivity from frontal to visual cortex, thus arguing for a crucial role of frontoparietal cortex in perceptual transitions during bistable perception.
authors.affiliation: Visual Perception Laboratory, Department of Psychiatry and Psychotherapy, Charité Universitätsmedizin, 10117 Berlin, Germany, and Department of Psychology, Humboldt-Universität zu Berlin, 10099 Berlin, Germany.
authors.forename: Veith A
authors.initials: VA
authors.lastname: Weilnhammer
authors.forename: Karin
authors.initials: K
authors.lastname: Ludwig
authors.forename: Guido
authors.initials: G
authors.lastname: Hesselmann
authors.forename: Philipp
authors.initials: P
authors.lastname: Sterzer
mesh_terms: D000328:Adult; D001931:Brain Mapping; D005260:Female; D005625:Frontal Lobe / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009039:Motion Perception / Q000502:physiology; D010296:Parietal Lobe / Q000502:physiology*; D010775:Photic Stimulation; D014795:Visual Pathways / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*